----- Original Message -----
From: "Steve Dimse" <k4hg at tapr.org>
To: "TAPR APRS Mailing List" <aprssig at lists.tapr.org>
Sent: Tuesday, December 07, 2004 10:31 AM
Subject: Re: [aprssig] APRS Symbols- Direction/Vectoring
On 12/7/04 at 8:22 AM Curt, WE7U <archer at eskimo.com> sent:
>Xastir has four rotations for each symbol. We do flip pixels.
>The problems I see with this are first, it only gives you 4 compass points,
second, it gives no indication of speed...so one of the 4 projections must
be
used as well when a station is not moving, and finally, some icons are
symmetric
about the vertical axis, for example the balloon, so these can only show two
values (east/west/stationary) and (north/south).
I much prefer the way MacAPRS has done it for the last 10 years, a vector
drawn
from the icon in the direction of travel, the length of the vector giving an
indication of speed. I need to work on this a bit, the red vectors can get
lost on maps using red for
roads:
http://www.findu.com/cgi-bin/plot.cgi?call=KC0NWI-1&vector=1&degree=1
Maybe I'll let the user specify a color. This is experimental, comments
welcome...
Steve K4HG
UI-View's speed sticks (okay, vectors) represent speed and direction. For
my map, I doubled the vector length so that I could see weather circulation
across the country. Works great!
Red vectors also conflict with Red NWS warnings....so being able to set the
color of the vector is a nice touch.
Jim, WA6OFT